1. Field of the Invention
This invention relates to a lubricant based on special hydrogen polyorganosiloxanes which provides synthetic materials with high surface slip which is retained for prolonged periods, even under severe stressing.
2. Background Information
Lubricants based on diorganopolysiloxanes, optionally in admixture with organic substances, such as waxes, for example, have been known and used for some time. Thus, according to U.S. Pat. No. 3,896,032, mixtures of diorganopolysiloxanes of different viscosity, which contain terminal R.sub.2 Si(OR')O.sub.1/2 groups (where R' may be a hydrogen atom or an alkyl radical), optionally in addition to terminal R.sub.3 SiO.sub.1/2 groups, are effective lubricants. According to U.S. Pat. No. 4,076,672, diorganopolysiloxanes obtained by emulsion polymerization, which have a viscosity of at least 20,000 cST at 25.degree. C., are used in admixture with waxes or organic, optionally substituted polymers. U.S. Pat. No. 4,434,008 describes oil-in-water dispersions of which the active component consists of 5 to 80% by weight silicon oil having a viscosity of 500 to 50,000 mP.s at 25.degree. C. and, for the rest, of wax, fatty acids, cationic imidazolinium salts and ethoxylated fatty amines. According to U.S. Pat. No. 4,561,987, polyether polysiloxanes are also said to show good lubricating properties.
Practical tests have shown that the lubricants described in the above-mentioned patent specifications, although capable of providing certain yarns, fibers, films etc. with the required properties, are unsatisfactory in their lubricating effect on certain substrates.
For example, artificial turf consisting of polypropylene fibers requires extremely high smoothness comparable with that of natural turf, a property which can only be imparted to artificial turf by treatment with a smoothing agent. In the absence of these properties, injuries and burns can be sustained by anybody falling and sliding on artificial turf. If artificial turf of the type in question is used in sport, particular importance is attributed to its smoothness in the case of sports requiring high skills. If, for example, artificial turf of the type in question is intended for a sports field, it must combine the surface slip discussed above with other properties specific to the particular sport. For example, where artificial turf is used for football pitches, it should not adversely affect the bounce or rolling behavior of footballs. Similar requirements exist in other sports. For example, the properties of artificial ski slopes or of artificial curling rinks should not differ significantly from those of their natural and well prepared counterparts. In addition, the required properties should remain immune for prolonged periods to severe stressing by the user and--in the case of open-air facilities--to atmospheric influences.